Commercial airplanes, more specifically high capacity transport aircrafts, comprise more and more electrical and electronic systems intended either for the aircraft's flight management and flight control, in the form of computers and control units or electrical power units, or for the comfort of passengers, such as multimedia devices, commonly referred to as IFE or “In Flight Entertainment”. These systems are most often located in the front portion of the aircraft near the cockpit, generally in the bottom portion of the fuselage, under the passenger entrance and cockpit floors, in a compartment called “avionics bay”.
There is redundancy for the systems essential for flight control, such that a failure cannot affect the aircraft's flight control capability. For this reason of safety, these systems must also be the subject of an electrical and mechanical segregation, between the main systems and the backup systems, so that an electrical event, such as a power surge, or a mechanical event, such as a projectile penetrating the fuselage, cannot affect the main systems and the backup systems at the same time.
The installation of these systems comprises closets, or systems cabinets, of parallelepiped shape, containing computers, electrical and electronic components generally in racks, as well as bundles of electrical cables, or harnesses, connecting these closets together, with the control unit for the cockpit or the cabin's IFE terminals. It also comprises cooling and ventilation devices for the closets. These various cabinets need to be accessible, from either the inside or the outside of the aircraft, in order to carry out component repair, replacement, inspection or maintenance operations.
According to the prior state of the art, these various systems are not installed in an area around the front landing gear compartment; there are at least two reasons for this:                this area is potentially subject to projections, either by taxiing over objects or by a tire bursting, during taxiing or in flight;        the area is obstructed by structural members such as struts, which limit the possibilities for installing bulky systems cabinets in this area while retaining accessibility to them.        
Thus, in the face of the large increase in systems, the need to increase the volume available in the avionics bay is reflected in an expansion of the nose compartment behind the landing gear compartment. This expansion results in an increase of the aircraft's aerodynamic drag and mass. Such consequences have a direct impact on fuel consumption and therefore on the operating costs and performance of the aircraft.